I am afraid we are in for a new round of casualities in Iraq, that W's numbers will not be able to withstand.
The magic 1000 number has been crossed, and will carry headlines for a day or two more. But casualties in Iraq are not going to be a significant factor in the election IMO. The people who understand that Iraq is part of the war on terror are not going to be swayed by casualties. Those against the war, aren't going to be more against it due to casualties. Those who aren't sure are probably not going to vote, or are not going cast a vote on the basis of the war.